In networks, in particular in communication networks, the provision of information about events occurred in the managed network (e.g. alarms, state changes, configuration/relationship changes) in almost real-time to Network Management System (NMS) operators is of crucial importance for ensuring the service level agreement (SLA) negotiated with customers.
That means for example, that in the case the communication between an Element Management System (EMS) and a super-ordinate Network Management System (NMS) fails, e.g. due to data communication network (DCN) problems or faults on northbound management interface (Itf-N) communication equipment as example, it is necessary to re-route the event reports so that operators working on NMS are able to receive the information without significant delay.
Further, today customers still have to cope with temporary interruptions of communication between Agent and Managers on different management hierarchy levels (due to network or communication entities problems).
The consequences thereof are, as examples, a loss of notifications, i.e. less network supervision capability and delayed corrective measures, as well as a need for time-lasting synchronization procedures after the re-establishment of the communication.
It is to be noted that in the present application some operations defined in 3GPP standards (for management of wireless networks via northbound interfaces) only serve as examples, but the principles of the invention are valid for all kinds of telecom networks, communication protocols or management hierarchy levels, i.e. not only between EMS and NMS.
In general, a Telecommunication Management Network (TMN) principles define several layers for the hierarchical management of telecommunication networks, while each layer may play a dual role:                Manager role (in “managing system”) for the subordinate layer (if available)        Agent role (in “managed system”) for the next higher layer (if available).        
For the day-to-day management of telecommunication networks usually two management layers are of special relevance:                The “Network Management” layer, whose functionality is provided by a Network Management Systems (NMS). In order to achieve a functional integration of different network areas (usually supervised by different, vendor-specific equipment) into a unique NMS, the interface between NMS and the (regional) Element Manager Systems (EMS) shall be vendor-independent.        The “Network Element Management” layer, whose functionality is provided by an Element Manager System (EMS, named also OMC) usually delivered by the same manufacturer like the managed Network Elements (NE). The EMS plays a Manager role with regard to the supervised network elements and provides Agent functionality to the superior NMS.        
With regard to new required services, to multi-vendor equipment environments, multi-technologies and multi-domains to be supported simultaneously, the management of telecommunication networks (taking as example of a networks) needs to cope with increased size and complexity of the controlled networks. The consequences thereof may be for example:                a) Moving end-to-end, more complex supervision functions on higher management levels, i.e. leaving only dedicated, often vendor-specific management activities to be done on lower management systems.        b) Usage of multiple NMS, while some network events are significant only for dedicated NMS and other ones for all NMS.        
An essential factor for efficient network supervision on NM level is the capability to synchronize the event information in the NMS with the current network condition. This is ensured by means of two interface communication patterns: event reporting, i.e. spontaneous forwarding of notifications in real-time, and request/response, while the reliable transmission of notifications in “near” real-time is especially significant.
The EMS interfaces to supra-regional NMS are provided by so-called Itf-N Agents, which transform the notifications generated in the managed NEs or in EMS itself according to the NMS-EMS object model (“event report mapping”) and forward them subsequently over Itf-N under consideration of filtering criteria defined by the subscribed NMS.
As mentioned above, the provision of information about events occurred in the managed network (e.g. alarms, state changes, configuration/relationship changes) in “near” real-time to NMS operators is of crucial importance for ensuring the SLA negotiated with customers.
In the current literature, the aspects of securing event forwarding on management interfaces in case of agent functionality or communication path failures are usually related to the provision of redundant EMS resources, i.e. redundant agent instance and redundant Itf-N equipment. This option is not an optimal one, due to the additionally needed physical & logical resources in each EMS and their related costs.